特异性氨基酸通过Vacuolar H+-ATPase-mTORC1轴调控脂代谢在修复糖尿病心功能损伤中的作用及机制

脂代谢增强是糖尿病性心肌病（DCM）的重要病理特征。脂肪酸转运蛋白CD36易位至细胞膜上摄取脂肪酸是脂代谢的关键起始步骤。CD36易位与Vacuolar-type H+-ATPase（V-ATPase）介导的胞内体pH密切相关。.我们前期发现心肌中某些氨基酸参与V-ATPase-mTORC1复合物形成，进而激活V-ATPase，抑制CD36易位。心肌中V-ATPase能否被氨基酸激活调节脂代谢？本课题拟利用DCM细胞/动物模型，1）揭示哪些氨基酸参与激活V-ATPase及机制（关键方法：同位素标记及免疫共沉淀等）；2）研究激活的V-ATPase对CD36介导的脂代谢、GLUT4介导的葡萄糖代谢及心功能的影响，并通过抑制V-ATPase活性验证该作用（关键方法：同位素标记、细胞膜蛋白生物素化、肌小节成像、间接测热、脂质组学及超声波心动描记等）。.本课题将为防治DCM提供新的视角和分子靶点。

Aberrant lipid metabolism (or progressive lipid uptake) is a prominent pathological feature of diabetic cardiomyopathy (DCM). In the heart, CD36 (the major fatty acid transporter) translocation to cell surface is a key initial step in lipid metabolism. Notably, CD36 translocation between endosome and cell surface is regulated by endosomal pH mediated by vacuolar-type H+-ATPase (V-ATPase). We previously found that some specific amino acids stimulate V-ATPase-mTORC1 supercomplex, which subsequently activates V-ATPase, thereby inhibiting CD36 translocation to cell surface. In our quest for strategies to against aberrant lipid metabolism in DCM, amino acids-stimulated V-ATPase could be a potential target for improving CD36 mediated-lipid metabolism..In the present research project, DCM cell/animal model are employed to investigate, 1) which specific amino acids activate V-ATPase and it’s molecular mechanism (key methods: stable isotope labeling and immunoprecipitation, etc.); 2) the effects of specific amino acids-stimulated V-ATPase on CD36-mediated lipid metabolism, GLUT4-mediated glucose metabolism, and cardiac function (key methods: stable isotope labeling, cell surface protein biotinylation, video-based cell geometry system for measuring sarcomere dynamics, indirect calorimetry, lipidomics, and echocardiography, etc.). Additionally, the validation experiments of these positive effects are conducted by inhibiting V-ATPase activity..Therefore, the main findings of this research project may offer novel insights and molecular targets against DCM.